<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="../js/vue.js"></script>
</head>

<body>
    <div id="app">
        <button @click.once="demo01()">点我啊</button>
    </div>
    <script>
        new Vue({
              el:"#app",
            methods:{
                  demo01(){
                      alert("单价事件执行了")
                  }
            }
        })
    </script>
</body>
</html>